Printed circuit boards and molded circuit boards are well known and are referred to generally as circuit boards. Some examples of molded circuit boards in the art are described in the following U.S. patents: U.S. Pat. No. 4,604,678 dated Aug. 5, 1986 by George R. Hagner entitled "Circuit Board with High Density Electrical Tracers"; and U.S. Pat. No. 4,080,513 by E. A. Cuneo et al dated Mar. 21, 1978 entitled "Molded Circuit Board Substrate".
In general terms, a molded circuit board is not unlike a conventional printed circuit board (PCB) in that it provides interconnections between electrical components mounted thereon. However, it does differ in that the electrical tracks on the circuit board consist of grooves recessed into the board surface.
One difficulty with circuit boards, either molded or of the PCB variety, is that they do not readily provide the capability of providing coaxial circuits. For straight electrical interconnection of components they work very well; but difficulties do arise when trying to form a coaxial conductor on a PCB or molded circuit board. The following U.S. patent refers generally to the construction of coaxial circuits on PCBs: U.S. Pat. No. 3,922,479 by R. B. Older et al dated Nov. 25, 1975 and entitled "Coaxial Circuit Construction and Method of Making".